Posters

Can NEI-VFQ25 questionnaire be used as an independent outcome measure to visual acuity in diabetic retinopathy trials?

Poster Details

First Author: R.Crosby-Nwaobi UK

Co Author(s): S. Sivaprasad

Abstract Details

Purpose:

To determine the correlation between NEI-VFQ 25 and visual acuity in different grades of diabetic retinopathy (DR) to examine the subscales that is responsible for the outliers.

Setting:

2 Tertiary ophthalmic centres in South London.

Methods:

372 men and women with T2D were stratified by severity of DR into no/mild retinopathy and severe non-proliferative or proliferative diabetic retinopathy (PDR). Each subject underwent tests of diabetes related distress (PAID), vision-related quality of life (NEI-VFQ25), best corrected visual acuity (BCVA)[LogMAR], ophthalmic and physical examination. Bivariate analysis between categories of DR; linear regression was conducted for the NEI-VFQ-25 by DR severity adjusting for age, gender, HbA1c and PAID were conducted using SPSS v17.

Results:

The mean NEI-VFQ-25 for the PDR group was significantly lower when compared to the group with no retinopathy, 86.2±10.7 vs. 75.8±20.4, p=<0.001, where lower score=decreased vision-related quality of life. BCVA (0.09±0.13 vs. 0.19±0.21, p< 0.001) and HbA1c (8.0±1.8 vs. 8.7±2.0, p=0.007) were also significantly different between the two groups of retinopathy. PAID was not significant between the groups. NEI-VFQ-25 was inversely correlated to LogMAR BCVA (r=-0.052, p<0.001) and PAID (r=-0.219, p<0.001). On full adjustment of the model, NEI-VFQ-25 was significantly associated with severity of retinopathy (no retinopathy: 84.3±1.1 vs. PDR: 79.0±191.2, p<0.001) but BCVA accounting for only 20% of the variance in the model.

Conclusions:

NEI-VFQ-25 is independently associated with severity of DR. Visual acuity only accounts for 20% of the variance seen in NEI-VFQ-25. Therefore, in clinical trials, the NEI-VFQ-25 may be used in preference to visual acuity as a better assessment of overall patient outcome as it evaluates different gross aspects of visual acuity (contrast sensitivity, near acuity, distance acuity) and quality of life rather than distance vision only and so should be considered as an independent outcome measure.